SMPD1 and Alzheimer disease: Several investigations have found elevated amounts of ceramide and activity of various SPL-metabolizing enzymes in the brain tissue of patients with AD (Crivelli et al. 2024) (Lee et al. 2014) leading to a variety of pathological features such as cell apoptosis (Smith and Schuchman 2008), neurogenesis loss (Gulbins et al. 2013), BBB leakage(Park et al. 2018), and inflammation (Chung et al. 2016; Bai and Guo 2017), indicating that ASM inhibition could be an important therapeutic target for addressing AD’s neuropathological features (Park et al. 2020; Park et al. 2022).